1. Field of the Invention
Embodiments of the invention generally relate to ballistic target defense and, more particularly, to anti-ballistic missile defense systems and methods that are non-provocative, accurate and reliable.
2. Description of Related Art
Ballistic missile defense (BMD) is one of the most technically challenging aerospace endeavors, and is of great strategic importance to many countries. The traditional approach to BMD employed by the United States of America, for example, evolved from the threat of USSR long-range bomber attack using land based missiles such as the NIKE, in a frontal attack scenario. The relatively large target size and comparatively slow speed of manned bombers enabled a frontal attack by land based anti-aircraft missiles to achieve a high kill probability. When the strategic threat shifted from bombers to Intercontinental Ballistic Missiles (ICBMs) in the 1960's, the frontal attack approach was retained for anti-ICBM defense with systems such as SPARTAN and SPRINT, two historic missiles related to the U.S. ABM defense system. However, the extremely small size of an ICBM warhead, its much greater hardness compared to that of a manned bomber, its flight environment for all but the launch and termination portions of its trajectory and, in particular, its much higher closing speed dramatically increased the difficulty of a successful frontal intercept.
The high kinetic energy of an ICBM warhead offers an approach to turn its high flight speed into a defensive advantage. At ICBM trajectory speeds of approximately 20,000 feet per second, the kinetic energy of each pound of the warhead is several times the energy of chemical explosives. Therefore, contact with any reasonably sized solid object will cause the warhead to vaporize. This physical principal has led to the development of sophisticated sensor and precision trajectory technologies required to “hit a bullet with a bullet” in a direct frontal attack. This approach of turning the target's high kinetic energy against itself enables a relatively small interceptor missile to accomplish the ballistic missile defense mission because the required interceptor speed change capability, ΔV, can be substantially less than the ICBM ΔV, and because the sufficient interceptor impact mass can be small compared to the mass of the ICBM warhead. Thus, the frontal attack kinetic energy approach to BMD trades the advantages of a potentially smaller interceptor missile and payload for the sensor and guidance challenges of locating and then hitting a ballistic missile warhead with closing speeds in excess of 20,000 feet per second.
Despite advances in sensor technology that have undoubtedly increased the kill probability of the frontal intercept approach to ballistic missile defense, defensive counter measures also continue to be developed. These counter measures may include, for example, the use of decoys such as balloons, locating warheads in a decoy, chilling or heating the decoys to mask their thermal signature, adding divert propulsion to the warhead, or adding an offensive capability that launches a mask in front of the warhead to destroy the interceptor's payload.
In recognition of the importance of ballistic missile defense and the challenges associated therewith, there is a need for an alternative BMD system and approach that utilizes existing and developing technology in tracking, guidance, and communications, and which is more reliable, accurate and cost effective than past approaches and those currently in use.